1. Field of the Invention
The present invention relates to a wireless communication area measuring apparatus and a computer program for designing a wireless communication area.
Priority is claimed on Japanese Patent Application No. 2007-088439, filed Mar. 29, 2007, the content of which is incorporated herein by reference.
2. Description of the Related Art
In a conventional technique, of a cellular system, a wireless communication area is extended by spreading macro/micro cells. In the near future, due to using higher frequencies, it can be easily forecasted that there will be an increase of trials of providing pico cells by setting base stations with low power which can be easily installed and each of which covers a small area in order to eliminate areas at which wireless communication is not available, for example, skip zones or blind zones made by buildings and the inside of buildings. On the other hand, even today, wireless local area networks (wireless LAN) which provide pico cells are generally used for wireless communication systems inside buildings. In such a pico cell system, in general, pico cells having a radius of several decade meters are spread and set on a two-dimensional area. However, there is a problem in which cell size and shape fluctuate because of objects inside the wireless communication area (for example, shape and location of buildings in the case of an outdoor area, and regarding indoors, structure of rooms, equipment and furniture inside the building in the case of an indoor area), and consequently pico cells are irregularly arranged. Due to such a problem, in practical cases, it is difficult to apply the prior art for controlling base stations as described in Patent Document 1 below which has an assumption of regularly arranging pico cells. Hence, there is a requirement for a technique of dynamically controlling base stations that can be applied to irregularly arranged cells in order to reduce interference among cells such as pico cells. Regarding such a requirement, in a conventional wireless LAN, a technique is generally known that estimates the cell shapes by applying a computer simulation based on a layout of rooms in which access points (AP) are set, and that controls and determines the arrangement of APs, the arrangement of frequency channels assigned to APs and transmission power of APs.    [Patent Document 1] Japanese Patent Application, First Publication No. 2005-27189    [Non-Patent Document 1] http://www.artiza.co.jp/product/isite/index.html (Artiza Networks Inc., possible to access in Mar. 26, 2007)
It should be noted that, in the above-described prior art of controlling base stations, the cell shapes are estimated by using a computer simulation based on a layout of the rooms. However, such a technique for estimating the cell shapes based on the layout of the rooms has not been sufficiently developed, and there is a problem in which the base stations cannot be appropriately arranged and controlled.
In addition, in the above-described prior art, it is necessary to input the layout of the rooms in detail and to accurately input materials (dielectric constants) of objects inside the rooms. Therefore, inputting such data for a computer simulation was a heavy load for operators, it was not easy to obtain a simulation result, and it took a long time to obtain a result.